Field
The invention relates to a video endoscope, and in particular to a video endoscope having a longitudinally extended endoscope shaft, in which a hermetically enclosed video-optical unit is arranged, wherein the video-optical unit comprises an enclosure, particularly an at least substantially cylindrical, hermetically sealed housing as an enclosure, having a distally arranged entry window, an objective lens, an image sensor unit, and one or more signal lines, wherein the housing is connected to an outer jacket tube of the endoscope shaft in a rotationally fixed manner, and wherein the image sensor unit is mounted in the housing rotatably about a longitudinal axis of the endoscope shaft and comprises at least one image sensor, and a video endoscope system.
Prior Art
Video endoscopes are designed elongated with a small cross-section. In generic video endoscopes, image sensors and the upstream optical systems are normally arranged in the distal region of the endoscope shaft, that is, in the region of the endoscope tip. Image signals and control signals are transmitted via signal lines to or respectively from the proximal end, that is, the handle.
The autoclavability of the endoscope is a basic requirement. During autoclaving, the endoscope is treated with hot steam under high pressure. In the case of optical endoscopes and in particular video endoscopes, it is necessary to protect the optical components and the image sensor from steam which would otherwise condense on the optical system during cooling and impair the optical quality of the system. Video endoscopes are therefore normally constructed in a hermetically sealed manner. The hermetic seal prevents steam from penetrating into the hermetically sealed region. With conventional video optical systems, this normally extends from the shaft tip into the handle.
With optical systems having a sideways viewing direction, which can also be rotated about the longitudinal axis of the endoscope, a rotation of the image sensor to the sideways viewing optical system, for example a prism unit, and thus the jacket tube, is necessary. The rotation of these two optical components with respect to each other occurs in the hermetically sealed space. The image rotation is generated by the user in the handle of the optical system and must be transferred up to the tip. Thus, the seal must be guaranteed from the handle up to the tip of the video endoscope. As a result, the space in the jacket tube is limited and is utilized in order to implement a hermetically sealed unit, to transfer an image rotation, to transport light, and to guarantee a mechanically resilient design. Each of these different requirements must be satisfied, such that the optimization of one requirement occurs at the expense of another requirement.
Because there are endoscopes with different lengths of the endoscope shafts and jacket tubes, a suitable video-optical unit, i.e., the unit which comprises the optical system with objective lens and the image sensor, must be produced for each endoscope. A modular design with different lengths, which could also be different nationally, is therefore expensive.